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<span id="Advanced-Real_002dto_002dreal-Transforms"></span><div class="header">
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Previous: <a href="Advanced-Real_002ddata-DFTs.html" accesskey="p" rel="prev">Advanced Real-data DFTs</a>, Up: <a href="Advanced-Interface.html" accesskey="u" rel="up">Advanced Interface</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
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<span id="Advanced-Real_002dto_002dreal-Transforms-1"></span><h4 class="subsection">4.4.3 Advanced Real-to-real Transforms</h4>

<div class="example">
<pre class="example">fftw_plan fftw_plan_many_r2r(int rank, const int *n, int howmany,
                             double *in, const int *inembed,
                             int istride, int idist,
                             double *out, const int *onembed,
                             int ostride, int odist,
                             const fftw_r2r_kind *kind, unsigned flags);
</pre></div>
<span id="index-fftw_005fplan_005fmany_005fr2r"></span>

<p>Like <code>fftw_plan_many_dft</code>, this functions adds <code>howmany</code>,
<code>nembed</code>, <code>stride</code>, and <code>dist</code> parameters to the
<code>fftw_plan_r2r</code> function, but otherwise behave the same as the
basic interface.  The interpretation of those additional parameters are
the same as for <code>fftw_plan_many_dft</code>.  (Of course, the
<code>stride</code> and <code>dist</code> parameters are now in units of
<code>double</code>, not <code>fftw_complex</code>.)
</p>
<p>Arrays <code>n</code>, <code>inembed</code>, <code>onembed</code>, and <code>kind</code> are not
used after this function returns.  You can safely free or reuse them.
</p>



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